I have charizard. As for the water type, I have seadra for the water type. Graveler has the rock smash and strength. Brought Butterfree (Lv 50) for the bug type. Pidgeot for flying to eliminate everything before MewTwo. Dragging along a Lv 25 Evee hoping to evolve it into an Umbreon which might be difficult.

Since FireRed is the Kanto region right? In Gen III. Assuming you have the national pokedex, you can plenty of Sableye because Phychic and Normal would not be able affect Sableye. If you do not have Pokemon E/R/S then use pokemon with the high SP.Def since it would use Phychic or Future Sight.